Transitioning from small numbers of neural depth recording electrodes to many thousands requires consideration not only of data management, but also how to non-destructively deliver these electrodes into the desired brain regions. Simply developing larger planar probes with more electrodes packed onto the surface invites increased immune response, likelihood of neuronal perturbation due to the presence of the large foreign substrate, and limited spatial sampling distributions. Here we propose to break the paradigm of mechanically stiff shuttles to insert electrodes, but instead will develop arrays of ultra-small 'slf-motile' electrodes that are each able to move to a target region under their own power, and with minimal perturbation of surrounding cells. This process is based upon electro-osmotic drives developed for microfluidics, which propel fluid along the electrode surface. We will investigate the device design and electrical optimization for guiding micron scale, flexible electrodes to specific locations. This will be complemented by organic electrochemical transistors as the recording elements, which are less sensitive to small sizes than metal electrode pads. The combination of minimal cell perturbation, ultra-small dimensions, and arbitrary three dimensional distributions will create a highly functional network of electrodes to record and modulate complex neural behavior throughout the brain. This non-perturbative, high-density sampling platform could have revolutionary impact both for fundamental neuroscience as well as clinical applications, such as brain-machine interfaces.